1. Field of the Invention
The invention herein relates to a device for exercising the human body and more specifically to a combination abdominal exercise machine and a stationary exercise bike.
2. Overview of Prior Art
A variety of art exists in the area of exercise devices and inclusive of the areas of bikes for aerobic conditioning as well as abdominal exercisers. What has eluded the art thus far is a functional combination device that provides the capability to adequately perform in both realms of fitness.
The most apparent attempt was made by Shirley in U.S. Pat. No. 4,534,553 where a pedal and crank assembly drove an eccentric cam. The cam articulated with a plurality of bearings on the posterior of the seat back of the machine. Movement of the cam caused an angular displacement of the seat back and therefore some type of upper body flexion of the user. One of the problems with the device is the point of rotation (14 in FIG. 1) of the seat back to the frame is located below the pad and the axis of rotation is a single pivot point.
The human body primarily undergoes trunk flexion by rotating the five lumbar vertebrae, each with respect to the adjacent vertebrae, including the fifth lumbar with the sacrum and the first lumbar with the twelfth thoracic vertebrae. This involves a translating center of rotation that runs aligned through the vertebral bodies, clearly above the seat. This misalignment would cause the user to slide on the seat back making it virtually non functional as a support for the user performing trunk flexion.
The second and most prevalent problem with the disclosure is that the cam causes the seat back to rotate up, which is driven by the pedaling motion. This means that the muscles of the user's legs are driving this movement, not the user's abdominal muscles. The movement may make the device somewhat enjoyable to use but it clearly does not function as an abdominal exerciser.
Another bike apparatus is disclosed by Zibell in U.S. Pat. No. 4,538,804 which includes an inclined slant board. Though the board could conceivably be used as a board for doing abdominal exercises, the board offers no support for the user during that movement. The disclosure specifies the purpose being to pull isometrically with the arms of the user while pedaling with the legs, not to function as an abdominal exerciser. The bench is also not disclosed to be able to be changed in angle, thereby disallowing the device to the used in a semi-recumbant position as an exercise bike, which would be most comfortable to most users.
An abdominal exercise device was disclosed by Abelbeck in U.S. Pat. No. 5,697,874 which includes a pad to place the pelvis of the user, creating a slight posterior rotation of the pelvis. The disclosure also specifies a mechanism that creates a translating center of rotation that is aligned with the vertebral rotation of the user's body during trunk flexion. The invention also includes a pad to support the head of the user, but the there is no device disclosed, nor anticipated to add an aerobic element of training to the device, specifically an exercise bike.
Another abdominal exercise device is disclosed in U.S. Pat. No. 4,729,562 by Pipasik. This disclosure relates only to a device that is intended to work the abdominal muscles of the user. The device uses two stationary pivots, one apparently near the lower chest of the user and the other near the hip. It is intended to stimulate the abdominal muscles by a flexion movement of a narrow region of the vertebral column and the hip. The latter would be primarily the hip flexor muscles, namely the Iliacus and the Psoas major, not the Rectus Abdominis.
Though the arcuate seat could place the user's pelvis in posterior rotation, it is the pelvis not the entire trunk that should be in constant slight flexion. The purpose of an abdominal exercise device is to cause the movement of trunk flexion. If, as here, the trunk is completely flexed before the exercise begins, there can be no flexion under load, because there is little if any flexion. The only realistic flexion could come from the hip, thus actuating the hip flexors, not the abdominal muscles. Therefore the disclosure would enable a device that is only marginally functional in terms of an abdominal exerciser and no suggestion to a combination with a device to provide aerobic exercise is made by the reference.
A unique device is disclosed by Mulenburg et al in U.S. Pat. No. 5,616,104 which includes a bike pedaling exercise apparatus. The disclosure includes the user being in a recumbent position but does not suggest to be used in any form of abdominal exercise. The device is intended to be used as a human centrifuge, the pedaling action causing the user to spin about an axis near the head of the user. The acceleration forces would be useful to counteract the effects of microgravity on persons exposed to an environment such as on prolonged space flights. As such, the addition of abdominal flexion would be of no value because the resistance to the user's muscles in this case is created by the effect of gravity on the body of the user. In a microgravity environment this is of little value.
A device is disclosed by Beistegui Chirapozu in U.S. Pat. No. 4,479,646 that incorporates a trunk vibration mechanism. The vibration mechanism is intended to provide a massage to the user during the exercise. The action of the vibrating mechanism is enabled as a result of the pedaling action of the exercise bike. It is unlikely that any benefit of massage is realized during exercise because the action of massaging a muscle enables it to relax while exercising a muscle causes it to contract. In any case, the vibrating mechanism that contacts the user's abdomen and lower back are adjustable to rigidly secure into place. Therefore the disclosed device does not suggest there be any form of abdominal flexion or other abdominal exercise be realized from the device.
A combination exercise bike is disclosed by Buchmann in U.S. Pat. No. 4,140,312 in that the pedal component can be adjusted into a variety of positions relative to the user. The user can sit in a variety of positions and actuate the pedals with the user's leg muscles. The device can also be oriented such that the user can actuate the pedals with the user's hands, thus exercising the muscles of the upper body. The combination does, in no way, disclose nor suggest functioning as an abdominal exercise device. There is a position that suggests two items (13 and 14 in FIG. 2) could support the body of the user, but it is clearly not intended nor conceivably capable of allowing for trunk flexion with a user positioned thereon.
The disclosure of semi-recumbant exercise bikes is disclosed in U.S. Pat. Nos. D362,699 and 5,031,900 by Heaton et al, and Leask respectively. It is clear that both disclosures are relative to exercise bikes alone and not suggested to include any form of abdominal exercise device therewith.